> What is near or close at all times and all places is Atman. Based on this
the term "upanishhad"
> can be interpreted in the following ways.
"upa" means something near. The word upaniShad more than refering to "being
close at all times", it refers to "that which is CLOSEST - one's own self".
"sad" as you said has the 3 meanings you mentioned:
shithiliikaraNam - to cause to decay (karaNam is an agent)
gamanam - to know (also, to go)
visaraNam - to destroy completely
[It is interesting to note that in Sanskrit, "gam" - to go is also used in
the sense of understanding - "na avagachchaami" means 'I do not understand'.
Even in English we say: "I did not get it" for something we don't
understand. Also here "sad" is the dhaatu - root verb. After a series of
operations that convert a dhaatu to a noun, it still remains as "sad".
upaniShad is a noun. "sad", due to rules of consonant conjunction becomes
"Shad" depending upon what letter precedes it.]
You have missed out "ni" in the word upaniShad. "ni" refers to
nischayaatmakam - well ascertained.
Putting all the above together we get,
upaniShad = "well ascertained (ni) knowledge (sad - gam) about one's Self
(upa) that causes to remove ignorance (sad - shitiliikaroti) and destroys
ignorance completely (sad - visarati) [without leaving any trace/possibility
of return]".
So upaniShad really means brahmajnaana. Just a book about geography is also
titled "Geography", so also the text that deals with "upaniShad" is also
called upaniShad. Both the subject matter and the text's name are
upaniShad.
Regards,
SVS
PS: I hope it was not superfluous to what you have already said.